Naloxone, ethanol, and the chlorpropamide alcohol flush.

The effects of ethanol and subsequent administration of intravenous naloxone were studied in double-blind, placebo-controlled fashion with a group of six male chlorpropamide alcohol flushers (CPAF) and a group of 13 nonflushing males. The effect of ethanol intoxication on fine motor control was measured by a typing test. When sober, the two groups performed in comparable fashion. When intoxicated, the CPAF group displayed significantly greater impairment than the nonflushing group as measured by typing errors committed in 3 min (CPAF: 55.4 +/- 10.1 errors, n = 12; vs. nonflushing: 15.6 +/- 2.3, n = 32; p = 0.0000015 by Student's unpaired t test). Chlorpropamide alcohol flushers appeared to be more sensitive to ethanol. Naloxone reversed this effect for individuals in the CPAF group (saline treatment: 51.0 +/- 11.7 errors per minute; vs. naloxone treatment: 23.7 +/- 4.2; p = 0.034 by Student's paired t test, n = 6). Naloxone had no effect in the nonflushing group. Unlike the normal, nonflushing group, the CPAF group demonstrated an increased sensitivity to ethanol that was partially antagonized by naloxone.